Valve mechanism for internal-combustion engines



D. F. ASBURY VALVE MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed Oct;9 1919 3 Sheets-Sheet 1 D. F. ASBURY VALVE MECHANISM FOR INTERNAL cMBUS-TION ENGINES Dec. 25, 1923.

Filed Oct. 9. 1919' 3 Sheets-Sheet 2 lllllllll. lllllllll Dec. 25, 1923.

D. F. ASBURY VALVE MECHANISM For: INTERNAL comauswzon ENGINES s Sheets-Sh'eet 5 Filed Oct. 9, 1919 Patented Dec. 25, i923.

aliases sins- VALVE MECHANISM FOR INTERNAL-COMBUSTION ENGINES.

Application filed October a, 1919. Serial No. 329,495.

1 0 aZZ whom it may concern .1

Be it known that I, DORSEY F. AsBURY, a citizen of the United States,residing at ll ashington, in the District of Columbia, have inventedcertain new and useful Improvements in Valve Mechanisms forInternal-Combustion Engines, of which the following is a specification.

My present invention relates to improvements in valve mechanisms forinternal combustion engines, and it aims to provide an arrangement forcontrolling the inlet of explosive mixture and the exhaust of theproducts of combustion which is simple in construction as well as highlyefficient in operation.

A particular purpose of the invention is to provide a valve mechanismthe operation of which will be controlled automatically by the intake ofexplosive mixture and the exhaust of the products of combustion wherebyit will operate smoothly irrespec tive of the speed of the engine.

Another purpose aimed to accomplish is to so construct and relativelyarrange the parts of a valve mechanism embodying the above namedfeatures as to reduce toa minimum and practically entirely eliminate thewaste of explosive mixture through the valve mechanism during operationof the engine.

The invention consists, essentially, in providing independent valves forcontrolling the intake and exhaust and further consists in theemployment, in conjunction with these valves, of another valve forseparating t two valves from the explosion chamber during compressionand firing periods of the engine and it is another purpose of theinvention to so construct and relatively arrange these three valves asto utilize a single spring as a closing means for each of them.

Further, it is a purposeof the invention to so construct and relativelyarrange the intake and exhaust valves as to utilize the impulse producedby the exhaust to open the exhaust valve, to force the intake valveagainst its seat and maintain it closed during the exhaust period, andto' delay closing movement of the exhaust valve until the exhaustsubstantially ceases, all of which action results in the engine beingrelieved of the greatest possible amount of burnt gases, the absence ofwaste of explosive mixture and an efficient operation of the enginegenerally. Valves constructed as herein disclosed, that is, valvesprovided with means to utilize the impulse produced by the exhaust forthe purposes just stated not only accomplish the purposes mentioned butpermit of a stronger spring being used to force them against their seatsthan would be possible in the absence of such means.

As a further purpose the invention aims to provide means to cushion theexhaust valve prior to the same reaching its limit of movement to bothclosed and open positions to thereby eliminate pounding of this elementand assure its smooth, noiseless operation and longevity.

The invention consists in other advantageous details of construction,combination and arrangement of parts as will be referred to moreparticularly hereinafter in connection withthe accompanying drawingswherein are illustrated the best embodiments of the invention known tome at present. The invention, however, is susceptible to modificationand change in various respects and I therefore reserve the right to makesuch changes from time to time as may be advantageous and as areincluded within the scope of the appended claims.

In the accompanying drawings 7 Fig. 1. is avertical section through aportion of an internal combustion engine and illustrating theapplication of one form of the improved valve mechanism, the partsthereof being shown in the position they occupy during compression andfiring periods of the engine.

Fig. 2, a perspective view of the valve mechanism, the parts thereofbeing separated.

Fig. 8, a view similar to Fig. 1 illustrating the relative positions ofthe valve parts during exhaust periods of the engine.

Fig. 4, a View similar to Fig. 1 illustrating the relative positions ofthe valve parts during intake periods of the engine.

Fig. 5, a view similar to Fig. 1 illustrating a slight variation in theform of the invention.

Fig. 6, a perspective of the intake valve disclosed in Fig. 5, and

Fig. 7, a horizontal section on the line 77 of Fig. 5.

Referring now to the drawings in detail, a portion of an internalcombustion engine'is indicated generally by the letter A and as showncomprises, as is usual, a cylinder 10, piston 11, and valve chamber 12.In the present instance the valve chamber is disposed laterally withrespect to the cylinder and provided with a, port 13 which provides ameans of communication between the cylinder and relatively separatedintake and exhaust passages 14 and 15 respectively. Threaded in anopening in the upper wall of the engine, in vertical alignment with theport 13, is a cap 16 which upon removal enables access to be had fromthe top of the engine to the valve mechanism. Carried by the cap 16 istheusual spark plug 17 The port 13 is restricted in diameter withrespect to the valve chamber 12, and below said port the wall of thechamber is cored out from the lower open end of the chamber throughout amajor portion of its length to a point where a shoulder 18 is formed,substantially in horizontal alignment with the dividing wall between theintake and ex- '4 haust passages 14 and 15.

A hollow cylindrical valve cage 19 of lesser external diameter than thediameter of the chamber 12 is provided with an externally threadedcir'cumscribing offset portion 20 which is screwed in the lower end of IP the chamber 12, the upper end of said cage being provided with acircumscribing flange 2-1,'which, when the cage, is in proper placewithin the valve chamber, abuts the shoulder 18 in fluid tightengagement. Internally the cage isof uniform diameter throughout itslength except that near its lower end a minor portion of its length isreduced in diameter by an inwardly directed annular boss 22. Between theoffset portion 20. and the flange 21 apertures 23. are cut in the wallof the cage to provide a means of communication between the inletpassage 14 and the interior of the cage, the passage 14 being at alltimes in: open communication with the space in the valve chambersurrounding thecage, as is apparent from an inspection of the drawings.

Housed by the cage 19 is an exhaust valve designated generally by thenumeral 24. This valve comprises a hollow cylindrical portion 25 closedat its lower end by a. Wall 26 and open at its. upperend as shown, saidcylindrical portion being provided with apertures- 27 similar to theapertures23 of the cage 19, while a stem 28 extends centrally from thelower face of the bottom wall 26 and is externally threaded as at 29.vA. valve seat 30 is formed around the upper open end of the portion 25and surrounding said seat and'the cylindrical portion 25 from which itlaterally projects is a flange 31, the upper surface of which is cuppedor dished at 32 and extended beyond the openend of the portion 25 in thedirection of the longitudinal axis of the valve, as at 33, bestillustrated in the sectional views. An axial bore 34 extends through thestem 28' and bottom wall 26.

When arranged in proper relation to the cage 19 the cylindrical portion25 of the exhaust valve fits snugly within the cage yet is freelyslidable therein longitudinally, the

length of the valve chamber between the upper surface of the boss 22 andthe port 13 being greater than the length of the exhaust valve betweenits upper open end and the bottom wall 26 to permit suchsliding movement; the stem 28 is. slidably engaged in the opening in the boss 22 andthe flange 31' is similarly engaged in the upper end of the valvechamber.

A portion of the 'dished surface 32 of the flange 31 near the valve seat30 is formed into a seating surface, which, when the exhaust valve isclosed, that is, at its limit of upward movement, contacts with a seat35 surrounding the port 13 below said port and denies communicationbetween the cylinder and the exhaust passage 15. In this posidisposed inalignment, permitting free com- Inun-ication between the intake passage14 and the interior of the valve.

Engaged with the threads 29 on the stem 28 is. a collar 36 provided witha lateral circumscribing flange37. This flange is slidably engaged inthe cage 19 below the boss 22 and cooperates with the boss to form adash pot. for cushioning closure of the exhaust valve.

Attached. to the bottom'26 is a pin 38 which is slidably engaged in anopening through the boss 22 and functions to prevent relative: rotationof. the, valve and ca e.

in intake valve is designated generally by the numeral 39 and comprisesa head 40 and a stem: 41. A seatingsurface 42 is formed on the head 40and when the valve is properly arranged with respect to the exhaustvalve 24 thi seating surface is designed to cooperate with the seat 30of the exhaust valve when the intake valve is closed, to denycommunication between the cylinder and the interior of the exhaustvalve. The stem 41 is of a length so that when. the intake valve isseated a very slight clearance of approximately a two-thousandths of aninch'is provided between the end of, the stem and the upper surface ofthe bottom 26 of the exhaust valve. It is possible to make thisclearance so slight rev that in effect the intake valve possesses pluralseating surfaces, the first between'the surface 42 and the seat 30 ofthe exhaust valve and the second between the lower end I of the stem 41and the upper surface of the,

bottom26 of the exhaust valve. The purpose of the slight clearance is-topermitra positive seal between the seating surface 42 and the seat 30.

The upper surface of the head is shaped to form substantially acontinuation of the seating surface of the exhaust valve when the inletvalve is closed, said upper surface of the head 40 being then curvedupwardly and terminated at the top of the head which is flat andprovided with an annular recess 43. The metal joining the head with thestem is curved gradually as shown at 44, and longitudinally through thehead and stem is formed a bore 45 corresponding in diameter to the bore34 of the stem 28 of the exhaust valve. 7

A valve seat 46 surrounds the port 13 above said port, that is betweenthe port and the cylinder, and cooperating with this seat is a cylindervalve 47. Said valve 47 is recessed in its under face to correspond inshape to the upper surface of the head 40 of the intake valve and therelative arrangement of these similarly shaped surfaces in such that aslight space exists therebetween when both valves are closed;

Projecting centrally from the lower face of the cylinder valve is anelongated stem 48 which passes through the bore 45 in the intake valveand through the bore 34 in the stem of the exhaust valve-and carries atits lower end an adjusting sleeve 49 which is lockedin place on the stembya nut 50.

A spring washer 51 of any desirable type is arranged in the annularrecess 43 of the intake valve head and exerts an influence tending torelatively separate the intake and cylinder valves, while a strongexpansion spring 52 is arranged between the adjusting sleeve 49 and thecollar 36 and exerts an influence tending to overcome the spring washer51 and maintain the cylinder valve normally seated.

Secured to any suitable manner to the cylinder wall is a bracket 53having an openingwithin which is slidably arranged a valve lifter 54actuated by a cam 55 on a cam shaft 56.

The form of the invention illustrated in Fig. 5 of the drawings differsbut Slightly from the form of the invention just described. In Fig. 5both the cylinder valve 47 and the head 40 of the intake valve areconstructed substantially flat, the latter being comparatively thin andto a certain extent flexible so as to more readily accommodate itselfto' its seat-s. In other respects the mechanism illustrated in thisfigure is a duplicate construction of the mechanism illustrated in theprevious figures of the drawings. Both mechanisms operate in the samemanner.

Having described the invention its operation will be apparent and is asfollows Suitable gearing (not shown) rotates the cam shaft 56 half asfast as the crank shaft (not shown) of'the engine. The parts of thevalve mechanism being in'the position shown in Fig. 1, let it be assumedthat a compressed charge of explosive mixture fills the cylinder headand that the same has been ignited by a spark from the plug 17.Expansion of the exploded gases forces the piston downward during whichmovement the cam shaft isgiven a rotation of ninety degrees. Just priorto the completion of this amount of m vement, however, a portion of thecam is arranged to contact with the valve lifter 54 and begins to movethe same upwardly. The upper end of the valve lifter coming in contactwith the nut 50 of the lower end of the valve stem 48 imparts an upwardmovement to said valve stem and acts to unseat the cylinder valve 47allowing the pressure existing in the cylinder to reach the uppersurface of the head 40 of the inlet valve 39. Only a very slight liftingor unseating movement of the cylinder valve is necessary to allow thepres sure within the cylinder to reach the head of the inlet valve. Thespring washer 51 therefore functions to maintain the inlet valve closedupon its seat during the slight initial unseating movement of thecylinder valve to prevent the exhaust pressure from making under theintake valve and unseating same. As soon as the exhaust pressure actsupon the upper surface of the intake valve its contact with its seatduring the remainder of the exhaust period is assured.

As the piston moves upward and the cylinder valve opens farther thepressure of the exhaust, being greater than the strength of the spring52, acts through the inlet valve to force the exhaust valve downward orin a direction to unseat the same against the action of said spring,thereby allowing the exhaust gases to escape from the cylinder to theexhaust passage 15.

As the exhaust gases flow through the port 13 they contact with thedished upper surface of the inlet valve head 40 and flange 31 of theexhaust valve and due to the curvature of said dished surfaces thedirection of flow of the exhaust current is deflected from the line ofleast resistance and an impulse action thus imparted to the dishedsurface to, move the exhaust valve to full open position against theaction of the spring 52, the action of the exhaust gases here beingsimilar to the action of steam imparting an impulse action to the vanesof a turbine engine.

- An advantage of particular importance to be noted in connection withthe provi sion of impulse receiving means on the ex-g haust valve isthat this valve is maintained open throughout substantially the entireexhaust period of the engine as determined by its arrangement of valveoperating cams and is delayed in its closing movement due to the factthat an exhaust current of very low velocity exerts a powerful impulseand therefore the valve will not begin to close under spring actionuntil the exhaust substantially ceases; also that a much strongerclosing spring is possible of use than would be permissible in theabsence of means to utilize the impulse produced by the ex-' haust' foropening the exhaust valve against the spring; 7

It will be apparent thatthe intake valve is maintained closed againstthe exhaust valve by the pressure of the exhaust and also by impulse andthat the dash pots function to cushion the exhaust valve in its movementfrom closed to open position.

With the cylinder valve maintained fully open by the cam and the exhaustvalve maintained fully open by the impulse produced by the exhaustacting on the dished surface of the flange 31, as'illustrated in vFig. 3of the drawings, the upper face of the adjusting sleeve 49 is slightlyspaced from the lower face of the stem 28 of the exhaust valve. U

Formed on the cam 55 is' a slight bulge 57 arranged to contact with thevalve lifter 5a and kick? the same upward at a time when the spring 52is ready to overcomethe impulse action of a weakened exhaust vcurrent.

This kick is transmitted through the sleeve 49 and stem 28 totheexha'ust valve and gives the valve an initial momentum in a closingdirection. It also'serves to break up any sticking action of the exhaustvalve within the cage 19. v

Once the exhaust valve is started on its movement in a closing directionthe spring 52 adds momentum to such movement until 2 it is arrested bythe cushioning eifect of the dash pot formed by the flange 37 and theboss 22.

With the vanishing of the exhaust pressure the inlet valve is held'closed during closing movement of the exhaust valve by its inertia. Whenthe exhaust valve is arrested in its closing movement, the momen tum ofthe intake valve causes it to leave its seat and travel freely up thestem 48' of the cylinder valve. The piston now having begun its intakestroke the suction thus created draws a new charge of explosive mixturefrom the intake passage 14 through the aperatures 23 and 27 and throughthe exhaust valve into the cylinder, the gases acting upon the intakevalve in a Well It being understoodin what manner the spring 52functions to close both the. exhaust and cylinder valves, by exerting apush on the former aiid a pull on the latter, it remains only to pointout that the pulli on the cylinder valv-e is transmitted through thespring washer 51 to the intake valve to maintain the latter seated tosee that the spring 52 functions to close all three valves, it beingunderstood that the washer 5l is not absolu ely essential to theoperation of tli'e valve mechanism but is merely included in thearrangement because of the element of safety it affords.

. Thecomp'act arrangement of the parts of the valve mechanism eliminateall spaces noticeable inother similar types of valve iiiechani'sms whereexplosive mixture might be lost during operation of the engine, and

due'to the arrangement of'thevalves and the f 1. Ina valve mechanism forinternal combustion engines, a spring closed exhaust valve, *means'.acted upon by the exhaust products to impart opening movement to thevalve, and a dished impulse receiving surface on the valve acted upon bythe escaping exhaust products to also impart opening'movement to thevalve,

21111 a valve mechanism for internal combustion engines,- an exhaustvalve having one portion thereof adapted to receive the impulse oftheexhaus-t products to open the valve, said portion also acting as theplunger element of a dash pot to cushion said valve as it approachesopen positlon.

3 .In a valve mechanism for internal combustion engines, an exhaustvalve havinga dished impulse receiving surface acted upon by theescaping exhaust products to impart opening" movement to the valve. 7

4'. In a valve mechanism, for internal combustion engines, an exhaustvalve, and an intake valve movable relatively to the exhaust valve andactuated by exhaust products to impart opening movement to the exhaustvalve.

* 5. In a valve mechanism for internal ing movement to the exhaustvalve, an

an impulse receiving surface on the exhaust valve acted upon by theescaping exhaust products to also impart opening movement to the exhaustvalve.

6. In a valve mechanism for internal combustion engines, a spring closedexhaust valve, an intake valve acted upon by the exhaust products toimpart opening movement to the exhaust valve, and an impulse receivingsurface on the exhaust valve acted.

upon by the escaping exhaust products to also impart opening movement tothe ex haust valve.

7. In a valve mechanism for internal combustion engines, an exhaustvalve, and an inlet valve seated on the exhaust valve and acted upon bythe exhaust products to impart opening movement to said exhaust valve.

8. In a valve mechanism for internal combustion engines, an exhaustvalve, and a relatively movable inlet valve seated on said exhaust valveand acted upon by the exhaust products to impart opening movement to theexhaust valve.

9. In a valve mechanism for internal combustion engines, a spring closedexhaust valve opened by exhaust products directly impinging against thevalve, and means for initiating closing movement of the valve inaddition to that imparted by its spring.

10. In a valve nechanism for internal combustion engines, a springclosed exhaust valve opened by exhaust products directly impingingagainst the valve, and cam means initiating closing movement of thevalve in addition to that imparted by its spring.

11. In a valve mechanism for internal combustion engines, a puppet valvemovable to closed position in one direction and an exhaust valve movableto closed position in an opposite direction, said valves beingrelatively independently movable, and a single spring normally urgingboth of said valves to a closed position.

12. In a valve mechanism for internal combustion engines, an exhaustvalve, a relatively movable intake valve carried by the exhaust valveduring closing movement of the latter, and free to move toward openposition by its momentum when the closing movement of the exhaust valveis arrested.

13. In a valve mechanism for internal combustion engines, a puppetvalve, an exhaust valve, a single spring for moving both of said valvesto closed position, and an intake valve movable relatively to saidpuppet valve and said exhaust valve and initially moved toward openposition by its momentum when closing movement of the exhaust valve isarrested.

14. In a valve mechanism for internal combustion engines, an exhaustvalve, and an intake valve maintained closed by its inertia against theexhaust valve during closing movement of the latter, said intake valvebeing free to move to open position by its momentum when closingmovement of the exhaust valve ceases.

157' In a valve mechanism for internal combustion engines, an exhaustvalve having a seating surface at one end thereof, and a dished impulsereceiving surface on said valve outwardly of the seating surface andextending beyond the seating end thereof in the direction of thelongitudinal axis of the valve.

16. In a valve mechanism for internal combustion engines, a springclosed exhaust valve actuated by the pressure of exhaust products toopen position, and a dished impulse receiving surface on said valveacted upon by the escaping exhaust products to delay closing movement ofthe valve.

17 In a valve mechanism for internal combustion engines, an exhaustvalve having a seating surface at one end thereof, and an impulsereceiving flange surrounding the seating surface.

18. In a valve mechanism for internal combustion engines, an exhaustvalve having a seating surface at one end thereof, and an impulsereceiving surface on said valve dis posed outwardly of said seatingsurface.

19. In a valve mechanism for internal combustion engines, an exhaustvalve, an intake valve for imparting opening movement to the exhaustvalve, and an impulse receiving surface on the exhaust valve acted uponby escaping exhaust products to also impart opening movement to theexhaust valve.

20. In a valve mechanism for internal combustion engines, a springclosed exhaustvalve, an intake valve seated thereon, and means wherebysaid exhaust valve is actuated to exhaust open status by exhaustproducts.

21. In a valve mechanism for internal combustion engines, a puppetvalve, an exhaust valve, an intake valve, and a single spring producingclosing movement of each of said valves.

22. In a valve mechanism for internal combustion engines. an exhaustvalve. and an intake valve seating against said exhaust valve, saidintake valve being unrestrained during its opening movement.

In testimony whereof, I affix my signature in the presence of twowitnesses.

DORSEY F. ASBURY.

Witnesses CARROLL BAILEY, HENRY P. BRIGHT.

